1. Field of the Invention
The invention relates to methods and devices for forming an anastomosis between two hollow bodies, and more particularly to forming an anastomosis using magnetic force.
2. Description of the Background Art
Despite the considerable advances that have been realized in cardiology and cardiovascular surgery, heart disease remains the leading cause of death throughout much of the world. Coronary artery disease, or arteriosclerosis, is the single leading cause of death in the United States today. As a result, those in the cardiovascular field continue to search for new treatments and improvements to existing treatments.
Coronary artery disease is currently treated by interventional procedures such as percutaneous transluminal coronary angioplasty (PTCA), coronary stenting and atherectomy, as well as surgical procedures including coronary artery bypass grafting (CABG). The goal of these procedures is to reestablish or improve blood flow through occluded (or partially occluded) coronary arteries, and is accomplished, for example, by enlarging the blood flow lumen of the artery or forming a bypass that allows blood to circumvent the occlusion. What procedure(s) is used typically depends on the severity and location of the blockage. When successful, these procedures restore blood flow to myocardial tissue that had not been sufficiently perfused due to the occlusion.
Another proposed treatment places the target vessel, e.g., a coronary artery, in direct fluid communication with a heart chamber containing blood, for example, the left ventricle. Blood flows from the ventricle into a conduit that is in fluid communication with the artery; as such, this treatment may be described as a ventricular bypass procedure. Benefits of this procedure include obviating the need to manipulate the aorta, for example, as is done when a side-biting clamp is used in a typical CABG procedure to create a proximal anastomosis between the bypass graft and the aorta. Clamping or otherwise manipulating the aorta places the patient at risk in some cases due to the likelihood that such manipulation will release embolic material into the bloodstream. Some challenges associated with this procedure include delivering and deploying the conduit in the patient""s body, properly positioning the conduit with respect to the heart chamber and the target vessel, and obtaining beneficial flow characteristics through the conduit and the target vessel.
A particularly challenging task that must be performed during CABG procedures (as well as some ventricular bypass procedures) is suturing the conduit to one or more vessels. As an example, one end of the conduit may be sutured to a source of blood, such as the aorta, a heart chamber or a blood vessel, while the other end of the conduit is sutured to the target vessel, such as a coronary artery or another blood vessel. The small diameter of the vessels involved (typically from 1 mm to 4 mm) makes creating a handsewn anastomosis a highly technical and time-consuming procedure. The difficulty in forming the sutured anastomosis is exacerbated when access to the target vessel is restricted or limited, as in a minimally invasive or percutaneous procedure. This problem also arises in non-cardiovascular applications that utilize handsewn anastomoses, for example, treating peripheral vascular disease or injury, creating AV (arteriovenous) shunts, etc.
While those in the art have proposed various anastomotic couplings intended to replace a sutured anastomosis, none has performed well enough to receive any significant level of acceptance in the field. Many of the proposed couplings penetrate or damage the target vessel wall acutely or chronically, do not remain patent, fail to produce a fluid-tight seal between the conduit and vessel, or are simply too cumbersome and difficult to deliver or deploy.
Accordingly, there is a need in the art for methods and devices for forming a reliable anastomosis between hollow bodies in a relatively quick, easy and repeatable manner as compared to handsewn anastomoses or anastomoses formed by prior art, suture-free devices.
According to one embodiment the invention provides a method using magnetism for forming an anastomosis between first and second different blood vessels in a patient. The method includes steps of selecting a first blood vessel in the patient""s body, the first blood vessel having a blood-carrying lumen, selecting a second different blood vessel in the patient""s body, the second blood vessel having a blood-carrying lumen, and using magnetic force to form an anastomosis between the first and second blood vessels and place the blood-carrying lumens in fluid communication.
According to another embodiment the invention provides a method using magnetism for forming a proximal anastomosis between a graft vessel and a patient""s aorta to place the graft vessel and the aorta in fluid communication. This method includes steps of providing a graft vessel having a blood-carrying lumen, forming an opening in the wall of the aorta, and attaching the graft vessel to the aorta to form an anastomosis that places the blood-carrying lumen of the graft vessel in fluid communication with the opening in the wall of the aorta. The anastomosis is formed at least in part via magnetic force.
According to another embodiment the invention provides a method for forming a magnetic port in a first hollow body located within a patient, the first hollow body having a lumen. The method includes steps of forming an opening in a wall of the first hollow body, the opening extending into the lumen of the first hollow body, providing a first component having an opening adapted to be placed in communication with the opening in the wall of the first hollow body, the first component being configured to produce or be attracted by a magnetic field, and forming a magnetic port into the first hollow body by positioning the opening of the first component in fluid communication with the opening in the first hollow body.
According to another embodiment the invention provides a method for increasing the flow of blood to a selected site in a patient""s arterial vascular system. This method includes steps of placing a first end of a conduit in fluid communication with the left ventricle, placing a second end of the conduit in fluid communication with the arterial vascular system at the selected site, connecting the first and second ends of the conduit together in fluid communication with each other, and maintaining the conduit in an open position for blood flow through the diastolic and systolic cycles of the heart.
According to another embodiment the invention provides a device for forming a magnetic port in a first hollow body having a blood-carrying lumen. The device includes a securing component having an opening adapted to be placed in communication with an opening in the wall of the first hollow body so as to be in fluid communication with the blood-carrying lumen of the first hollow body. The securing component is generally plate-shaped and is configured to be secured to the first hollow body and withstand exposure to blood. The securing component is also configured to produce a magnetic field and form a magnetic port in the first hollow body.